SoPC Based Digital Current-Mode Control of Full-Bridge Phase-Shifted DC/DC Converters with Fast Dynamic Responses

Abstract

This paper proposes a SOPC (system-on-a-programmable-chip) solution for the digital current-mode control of a full-bridge phase-shifted (FB-PS) DC-DC converter to achieve fast dynamic response. The digital current-mode control scheme consists of several parts: a digital phase-shifted PWM generator to generate programmable phase-shifted PWM signals, a digital current controller, and a digital voltage controller through which an adaptive gain adjustments scheme could adjust controller parameters to achieve a fast dynamic response of the output voltage, and with a synchronous current sampling scheme to avoid switching noise and spike. The implementation of the proposed digital current-mode controller was realized by using a mixed-signal FPGA A2F200 from Microsemi SmartFusion. Experimental results are given to verify and show the feasibility of the proposed control scheme to a 800W, 400V to 12V DC-DC dc-dc converter in applications to high-performance server power supplies.